1. Field of the Art
The present invention relates in general to a heat-pipe device and a heat-sink device, and in particular to such a heat-pipe and a heat-sink device which are advantageously used for cooling a member generating a large amount of heat, such as a large-capacity semiconductor element.
2. Related Art Statement
A large-capacity semiconductor element, such as a large-capacity thyristor or transistor, generates a large amount of heat in a short time. For the purpose of sufficiently cooling such a semiconductor element, a semiconductor-associated heat pipe or heat sink is required to have a large heat-transmission capacity. Such a heat pipe must have a plurality of passage pipes in which a fluid flows for transmitting heat generated by the semiconductor element.
There are known various kinds of heat pipes. For example, a Japanese Patent Application (laid open in 1985 under Publication No. 60-26268) discloses a heat pipe which includes a plurality of separate passage pipes, together with a fin member and a plate member which are attached to the passage pipes. Another conventional heat pipe is of a type in which a plurality of passage pipes are in communication with each other by way of a pair of communication header pipes, and in which a fin member and a plate member are attached to the passage pipes. The third heat pipe known in the art is manufactured in a so-called "roll-bond" process, in which a plurality of passages are formed between a pair of plate members which are rolled under pressure. The fourth example of the conventional-type heat pipes includes an extrudate member which has therein a plurality of flow passages, and a pair of header pipes which are attached to the extrudate member.
However, the first example disclosed by the Japanese Patent Application has a problem of having a comparatively high heat resistance at the connections between the passage pipes and the plate and at the connections between the passage pipes and the fin member. Another problem with the first example is that its heat-transmission capacity is comparatively low at any local portions, since the passage pipes are separate from each other.
The second example above indicated has a higher heat-transmission capacity than the first one, since the second heat pipe has the communication header pipes for communicating the plurality of passage pipes. However, the second example has a problem, like the first one, that its heat resistance is comparatively high at the connections between the passage pipes and the plate member and at the connections between the passage pipes and the fin member.
The third example has a simple structure in which the plate members serve as passage-defining members, but suffers a problem that fin-defining portions formed adjacent to the passages are comparatively small.
The fourth heat pipe identified above has no plate member, and therefore it is impossible to directly fix a heat-generating member to the heat pipe.